- Peel off the skin of the large sized plantains and put them in water. Pour sour curd into this water. Leave this for half an hour. Strain the excess water off. Heat oil in a wide pan. Bring it to heat Slowly, slice the unriped banana using a chips slicer directly into this oil. When it is cooked, sprinkle some salt water and continue stirring. Turn over the chips to cook both the sides. Once sure that they are crisp, use a strainer to take the chips out and place them on an absorbent paper to drain the excess oil off. Serve.